In a factory automation (FA) field, a technology for inspecting an external appearance of an object to be inspected by using a camera has been developed. Regarding this technology, JP 2000-180382 A (Patent Document 1) discloses a visual inspection device that can inspect, at a high speed, a surface of an object to be inspected randomly placed on a conveyor. More specifically, the visual inspection device captures an object to be inspected conveyed on a conveyor from different directions with a plurality of cameras. The visual inspection device then inspects the object to be inspected by using input images obtained by capturing the object to be inspected from different directions.
Patent Document 1: JP 2000-180382 A